In attempts to overcome the deformation problem in containers holding volatile organic substances or gas absorbing contents numerous approaches have been attempted.
One such approach has been to form containers of substantially thicker cross section than previously used to forestall deformation or buckling of the sidewall and adjacent areas upon partial evacuation. This approach necessitates the use of substantially more resin than a lighter weight container. Accordingly, the heavier containers are more costly to produce based upon resin cost per container.
Other attempts have been made to forestall transfer of the volatile organic substances across the container wall by using biaxially oriented containers of high barrier resins, such as, polyvinyl chloride, acrylonitrile and the like. The highly oriented containers of high barrier materials have also shown a tendency to buckle or to collapse in the label panel area as evaporation or headspace degasing occurs, with the associated stress crazing or cracking of the adjacent area to the label panel or the sidewall.
Yet another method to forestall label area collapse involves the use of structural reinforcement ribs about the circumference of the container. Such rib reinforced containers are generally limited to the circular cross section. The cross sectional limitation causes severe design choice limitations.
One design, shown in U.S. Design Pat. No. 259,181, shows a container having a novel ornamental design including a raised portion at the top and bottom of the label panel area.